1. Field of Invention
The invention disclosed herein relates generally to the field of treating organic waste sludges to reduce and/or remove viable pathogens and/or vector attraction, so that such sludges may be safely and beneficially reused. More particularly the invention disclosed herein relates to conversion of said sludges, which are inherently highly nutritious to plants, into a safe, enriched agricultural medium. With more particularity the invention relates to conversion of the sludge into a form that is convenient to use, and is conditioned to improve the ability of plants to extract nutrients from the rich organic materials included therein.
2. Description of Prior Art
Organic waste sludges presently constitute a substantial problem in many areas of the world. Such wastes are by-products of municipal and private waste treatment plants, feed lot operations, sawmills, paper mills and many other industrial operations.
A problem with such organic sludges is that they provide an excellent growth medium for many types of potentially pathogenic bacteria, which are almost inevitably introduced into said sludges by the influent waste. Accordingly, raw organic sludges can be dangerous to human, animal and plant life, and proper disposal or reuse of them constitutes a substantial problem.
Said sludges are also typically odoriferous, have substantial vector (pests, such as rats, mice, roaches and some birds) attraction, and exist in the form of a sticky, wet, cohesive mass. These characteristics substantially limit where such sludges may be acceptably disposed, make dispersion difficult and entail the risk of vectors widely dispersing any pathogens remaining in the sludge.
However, the nutritious properties of organic sludge which cause potentially pathogenic organisms to flourish, also provide a potentially highly beneficial use for said sludge, as an agricultural enriching medium, provided that the potentially pathogenic organisms, vector attraction and difficult handling characteristics can be significantly improved.
A number of methods, described in 40 CFR Part 257, are known to reduce pathogens. These include aerobic digestion, anaerobic digestion, lime stabilization, air drying, composting, heat drying, heat treatment, gamma irradiation, electron irradiation and the methods shown on Table 6-1 of said regulation. In addition thereto U.S. Pat. Nos. 5,281,341 and 4,793,927 to Reimer's disclosed methods for treating waste sludge with nitrous acid or ammonia. All of the previously known methods involve one or more of the following disadvantages:
a) substantial time of treatment, PA1 b) high energy usage, PA1 c) substantial use of complex and expensive equipment, and, PA1 d) transport of pathogen bearing sludges to a permanently located treating facility.
The invention disclosed herein substantially reduces these disadvantages by providing a fast, simple, inexpensive method of treating organic wastes, on site, with simple, portable equipment. The invention further teaches recycling of the treated sludge into an agricultural medium of highly beneficial characteristics.
3. Objects of the Invention
The principal object of the invention is to provide a process by which organic waste sludges can be quickly and cheaply treated to remove and/or reduce potentially pathogenic bacteria, and eliminate or reduce vector attraction. Another object of the invention is to provide a highly beneficial product and process for making said product, which effectively makes said treated sludge recyclable as an agricultural medium and/or soil enriching/conditioning agent.